Metal rings for active brazing in sodium-based thermal batteries

摘要

The present application provides for metal rings and ceramic collars for active brazing in sodium-based thermal batteries. The metal rings may be outer and inner Ni rings configured for sealing to an alpha-alumina collar via active brazing for use in NaMx cells. The inner and outer Ni metal rings may be sealed to differing portions of the alpha-alumina collar. The portions of the outer and inner Ni rings active brazed to the alpha-alumina collar may define a tapered thickness that reduces internal stresses at the active brazed joints resulting from differing coefficients of thermal expansion between the Ni metal rings and the alpha-alumina collar. The portions of the outer and inner Ni rings and alpha-alumina collar sealed by active brazing, and thereby the active braze joints themselves, may be oriented to control or dictate the stresses on the joints during use.

主权项

1. A sub-assembly for at least partially sealing a cell of a sodium-based thermal battery, the sub-assembly including:
an outer metal ring defining a first aperture and including a first portion and a second portion, the second portion defining a length and a thickness, wherein the thickness of the second portion tapers along its length; an inner metal ring defining a second aperture that is smaller than the first aperture of the outer metal ring and including a third portion and a fourth portion, the fourth portion defining a length and a thickness, wherein the thickness of the fourth portion tapers along its length; and a ceramic collar defining a third aperture and including a first surface and a second surface, wherein at least a portion of the second portion of the outer metal ring is joined to the first surface of the ceramic collar by active brazing, wherein at least a portion of the fourth portion of the inner metal ring is joined to the second surface of the ceramic collar by active brazing, and wherein the ceramic collar substantially electrically insulates the outer and inner metal rings.